1. Technical Field
The present application relates generally to an improved data processing system and method. More specifically, the present application is directed to a system and method for generating a worst case current waveform for testing of integrated circuit devices.
2. Description of Related Art
The performance and power dissipation of an integrated circuit device depends on multiple factors. For example, operating temperature, the process used to fabricate the integrated circuit device, and operating voltage all affect how the integrated circuit device will perform and the power that the integrated circuit device dissipates. Performance tends to vary with process linearly, varies with operating temperature in an inverse logarithmic relationship, and varies with operating voltage exponentially. Power dissipation tends to vary with process somewhat linearly, with operating temperature exponentially, and with operating voltage exponentially. With these relationships, it can be seen that it is important in the design of modern integrated circuit devices to determine the lowest supply voltage, i.e. VminF, in order to guarantee that the integrated circuit device will function with the least power dissipation.
Typically, in order to determine the lowest supply voltage, worst case current waveforms (di/dt) are usually used to test an integrated circuit device, where di/dt represents the change in current over time. The determination of the worst case current waveforms (di/dt) is typically left to a human designer's educated determination of the workload on the integrated circuit device which will cause the most power consumption. Since it is left to the human designer to determine this worst case current waveform, human error may be present in this determination.
In order to ensure that the integrated circuit device will support the worst case operating scenario, i.e. the worst case current waveform, a guard band is typically added to the empirically determined minimum supply voltage VminF. The guard band is typically estimated based on the human designer's educated extrapolation of the results obtained during testing of the integrated circuit device. Thus, there may be considerable uncertainty in the estimation of the guard band to apply to the empirically determined minimum supply voltage VminF, as well as the uncertainty in the determination of the worst case current waveform.